INSECTS, HARMFUL AND OTHERWISE 



213 



lancing and sucking organs. They are modified mandibles 

 and maxillae, which can be folded together into a sucking 

 tube. The female " sings," but the male is silent. 



In many places malaria is a burden to the people. It is 

 now believed that mosquitoes carry the germs of the disease, 

 and implant them in man when they bite. It is not the 

 common mosquito, Culex, that is responsible for this, but 

 the genus Anopheles. This genus may be distinguished from 



FIG. 72. Development of a Mosquito. 



Egg mass, enlarged egg, hatched out larva, pupa, and adult emerging from pupa case. 

 (After Howard, Miall, etc.) 



the common mosquito by the fact that it seems to stand upon 

 its head when at rest, while the common form stands as a 

 well-behaved mosquito should, with the body parallel to the 

 resting surface. 



It has also been determined that the mosquito is a carrier 

 of yellow fever. After biting a fever patient a mosquito bites 

 a healthy person, who then contracts the disease. 



These facts make the checking of the development of the 

 mosquito a very important problem. Screens on doors and 

 windows are very effective in keeping them out of the house. 



